4-substituted-1, 1, 2-tricyano-1, 3-butadiene and process of preparation



United States Patent 3,040,084 4SUBSTITUTED-1,LZ-TRICYANO-LS-BUTADHENEAND PROCESS OF PREPARATION John K. Williams, Wilmington, DeL, assignorto E. I. du Pont de Nernours and Company, Wilmington, Del., a

corporation of Delaware No Drawing. Filed Apr. 25, 1960, Ser. No. 24,24319 Claims. (Cl. 260-465) The present invention is concerned with a newclass of colored organic chemical compounds useful as dyes, and moreparticularly with selected 4-substituted-1,l,2-tricyano-1,3-butadienesand to a process for their preparation.

With the continued discovery of new synthetic fibers and the expandinguse of these materials in clothing fabrics where colors and designs areof prime importance, there is an ever increasing need for new dyes withnew chromophoric structures and with chemical characteristics whichadapt them to new uses.

It is an object of this invention to provide a new class of coloredorganic chemical compounds useful as dyes. Another object is to provideselected 4-substituted-1,l,2- tricyano-l,3-butadienes and a novelprocess for their preparation. Other objects will appear hereinafter.

These and other objects of this invention are accomplished by providingthe new class of 4-substituted-1,1,2- tricyano-1,3-butadienes having theformula N where R and R are hydrogen or hydrocarbyl groups free ofaliphatic carbon-to-carbon unsaturation, Ar is arylene, and R is ahydrocarbyloxy group free of aliphatic carbon-to-carbon unsaturation. Ris a hydrocarbyl group free of aliphatic carbon-to-carbon unsaturation.This new class of 4-hydrocarbyloxyaryl-l,1,2-tricyano-1,3-butadienesincludes the 4-alkoxyaryl-l,1,2-tricyano-1,3-butadienes, the4-aryloxyaryl-1,l,2-tricyano-1,- 3-butadienes, the4-aralkyloxyaryl-1,1,2-tricyano-l,3-butadienes, the4-alkaryloxyaryl-1,1,2-tricyano-l,3-butadienes and the4-cycloalkyloxyaryl-l,LZ-tricyano-1,3-butadienes.

The new class of 4-hydr0carbyloXyaryl-l,1,2-tricyano- 1,3-butadienes ofthis invention can be prepared by a process in which the ring of thecorresponding 3-hydrocarbyloxyaryl-l,1,2,2-tetracyanocyclobutane isopened. In this novel process a3-hydrocarbyloxyaryl-1,l,2,2-tetracyanocyclobutane is heated in thepresence of an alkanol, preferably a lower alkanol, such as methanol orethanol. Temperatures in the range of 25 to 200 C. and above may beemployed and temperature in the range of 50-100 C. are preferred. It isconvenient, though not essential, to employ an excess of the alkanol asa reaction medium.

The process can be illustrated generically by the following equation:

in which the Rs are as previously defined.

When R and R are hydrogen, the process can be illustrated by thefollowing equation:

where Ar is arylene and R0 is a hydrocarbyloxy radical free of aliphaticcarbonto-carbon unsaturation, such as alkoxy, aryloxy, aralkyloxy,alkaryloxy, and cycloalkyloxy radicals.

The 3 hydrocarbyloxyaryl l,l,2,2 tetracyanocyclobutanes are prepared bycondensation of tetracyanoethylene with the correspondinghydrocarbyloxyarylethylenes as illustrated in Part A of Example I. Thereaction of tetracyanoethylene with a hydrocarbyloxyarylethylene willoccur simply on intimate contact of the reactants at room temperature.No additives or special conditions are needed. It is convenient, thoughnot essential, to employ a diluent which is inert to the reactants andproducts to aid in dissipating the heat of reaction. Pressure and theproportions of reactants are not critical and may be varied widely. The3-hydrocarbyloxyaryl-l,l,2,2-tetracyanocyclobutane reactants include3-alkoXyaryl-, 3-aryloxyaryl-, 3-aralkyloxyaryl-, 3-alkaryloxyaryland3-cycloalkyloxyaryl-Ll,2,2-tetracyanocyclobutanes.

The hydrocarbyl groups represented in R, R and R in the startingmaterials and products indicated above can be any radical composedsolely of carbon and hydrogen and being free of aliphaticcarbon-to-carbon unsaturation. Hydrocarbyl is used in its full genericsense. The term hydrocarbyl is consistent with chemical nomenclature andis synonymous with the term hydrocarbon radical. The wide variation inthe hydrocarbyl groups used in the illustrations which follow makes itevident that all hydrocarbyl groups free of aliphatic unsaturation areoperable. Hydrocarbyl groups free ofaliphatic carbonto-carbonunsaturation include alkyl, cycloalkyl, aryl, aralkyl, alkaryl, singlering, multi ring, straight chain, branched chain, large, small, and thelike. All aliphatically saturated hydrocarbyl radicals in the3-hydrocarbyloxyaryl-l,l,2,2-tetracyanocyclobutanes pass through theprocess of this invention and appear unchanged in the product. Thewidest variation in these hydrocarbyl radicals free from aliphaticcarbon-to-carbon unsaturation does not prevent the formation in thisprocess of the products of this invention.

The limitations of space for disclosure are not to be construed as anylimitation of the scope of hydrocarbyl contemplated in this invention.Even the most cumbersome saturated hydrocarbyl radicals such as thoseobtained by removing end groups from high molecular weight hydrocarbonpolymer molecules containing thou sands of carbon atoms, such aspolyethylene, polyisobutylene, polystyrene, and the like, are fullyoperable.

It is obvious that aliphatically saturated hydrocarbyl groups containing20 or fewer carbon atoms are most available, and to that extentpreferred. But there is to be no question of the operability of, or ofthe intent to include and disclose, any hydrocarbyl group whatsoever, aslong as it is free of aliphatic carbon-to-carbon unsaturation. Widevariations in size and structure of these hydrocarbyl radicals do notaifect the ability of the butadienes to which they are attached to beused as dyes.

By arylene we mean generically any divalent aromatic radical. It is ofthe essence of an arylene radical that the two bond stem from diiferentring carbon atoms. Among arylene radicals are included those from whichthe corresponding aromatic compound obtained by placing hydrogens at therespective bonds of the arylene group, i.e., the parent compound whosevalences are all satisfied, has a resonance energy of not less than 20kcal./ mole. Resonance energies of organic compounds and thedetermination of resonance energies are shown by Linus Paulin g in TheNature of the Chemical Bond, Second edition, Cornell University Press,1945, pages 132l39.

Arylene groups particularly suitable in the compounds of this inventionare those containing 20 or fewer carbon spa e-s4 atoms and include thehydrocarbon arylenes, particularly phenylene, naphthylene, andanthrylene.

In the following example parts are by weight except where otherwiseindicated. The example represents a preferred embodiment of thisinvention.

EXAMPLE Part A To a solution of 450 parts of tetracyanoethylene in 1776parts of tetrahydrofuran at C. is added 497 parts of p-methoxystyrene.The deep blue color which forms immediately upon mixing fades to grayand a solid precipitate starts to form within about minutes. Afterminutes, the cold solution is diluted with 3300 parts of petroleum etherand stirred at 0 C. for another 15 minutes. The solid precipitate iscollected by filtration and washed with petroleum ether. The crudematerial weighs 830 parts. It is recrystallized two times from1,2-dichloroethane to yield 3-(p-methoxyphenyl)-1,l,2,2-tetracyanocyclobutane, melting at 182-183 C.

Part B A mixture of 50 parts of 3-(p-methoxyphenyl)-l,1,2,2-tetracyanocyclobutane and 793 parts of methanol is heated at reflux.After two hours dark red crystals are seen forming in the mixture. Aftera total of 24 hours at reflux, the mixture is cooled to 0 C. and 29parts of 4-(p-methoxyphenyl)-1,1,2-tricyano-1,3-butadiene is obtained inthe form of dark red crystals. This is collected by filtration, washedwith methanol, and recrystallized twice from acetonitrile to yield apurified product melting at 214.5215.5 C. The infrared absorptionspectrum of this product shows bands at 4.51 microns (conjugated CN),6.31 and 6.57 microns ((:C), 6.20 and 6.69 microns (benzene ring), andat 11.95 microns (1,4-disubstituted benzene). The ultraviolet absorptionspectrum of an acetonitrile solution of the product shows peaks at 278millimicrons (molecular extinction coeflicient 8,840), 445 millimicrons(molecular extinction coefiicient 38,500) and shoulders at 303 and 320millimicrons.

Analysis.-Calcd. for C H N O: C, 71.49; H, 3.86; N, 17.87; M.W., 2.35.Found: C, 71.57; H, 4.02; N, 17.82; N.W., 260.

When the hydrocarbyloxyaryl substituted ethylenes shown in the firstcolumn of the following table are used in place of p-methoxystyrene inthe procedure of Part A of the example, there are obtained the3-hydrocarbyloxyaryl-l,1,2,2-tetracyanocyclobutanes of the second columnwhich on ring opening with methanol as shown in Part B of the exampleyield respectively the4-hydrocarbyloxyaryl-l,1,2-tricyano-1,3-butadienes shown in the lastcolumn.

TABLE Butadiene formed on ring opening with methanol Hydrocarbyloxyary]substituted ethylene 3-hydr0carbyloxyaryl- 1,1,2,2-tetracyanocyclobutaneIntermediate o-methoxystyrene p-ethoxystyrene p-phenoxystyrene.

pmethoxystilbene 3-(o-1nethoxyphenyD- 1,1,2,2-tetracyanocyclobutane.

3-(p-ethoxyphenyl)- 1,1,2,2,-tetracyanocyelobutane.

-(p-p e m e r 1,1,2,2tetracyanoeyclobutane.

3-(p-methoxyphenyl) 4-phenyl-1,1,2,2- tetraeyanocyclobutane.

4-(0-meth0xypheny1)- 1,1,2-tricyal10-l,3- butadiene. 4-(p-ethoxypheny1)-1,1,2-trieyan0-L3- butadiene. 4-(p-phen0xyphenyD- 1,1,2-trieyauo-1,3-butadiene. 4-(p-n1ethoxyphenyh- 3-phenyl-1,1,2-tricyano-1,3-butadiene.

All hydrocarbyloxyaryl butadienes of this invention 4 EXAMPLE A Asolution of 2 parts of 4-(p-niethoxyphenyl)1,1,2-tricyano-1,3-butadienein a mixture of 10 parts of 6 N aqueous hydrochloric acid and 235 partsof acetonitrile is added to a solution of 2 parts of a sulfonated lignindispersant in 2000 parts of water. The whole is made up to a total of20,000 parts by addition of water. The resulting dye bath has a pH of 5.Cloth swatches made of cellulose acetate, nylon, silk, and wool areadded and the bath is heated at 100 C. for 30 minutes. The clothswatches are rinsed with water and dried. By this treatment thecellulose acetate is dyed yellow-orange in color; the nylon is dyedbeige; the silk is dyed golden brown; and the wool is dyed tan.

As many apparently widely different embodiments of this invention may bemade without departing from the spirit and scope thereof, it is to 'beunderstood that this invention is not limited to the specificembodiments thereof except as defined in the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A 4-hydrocarbyloxyaryl-1,1,Z-tricyano-1,3-butadiene having theformula R R ON CN where R and R are hydrocarbyl groups free of aliphaticcarbon-to-carbon unsaturation, Ar is arylene which is entirelyhydrocarbon of no more than 20 carbons and has the two bonds stemmingfrom diiferent carbons of the arylene ring, and R0 is a hydrocarbyloxygroup free of aliphatic carbon-to-carbon unsaturation.

3. A 4-hydrocarbyloxyaryl-1,l,Z-tricyano-1,3-butadiene having theformula where one of the groups R and R is hydrogen and the other is ahydrocarbyl group free of aliphatic carbon-tocarbon unsaturation, AI isarylene which is entirely hydrocarbon of no more than 20 carbons and hasthe two bonds stemming from different carbons of the arylene ring, andR0 is a hydrocarbyloxy group free of aliphatic carbon-to-carbonunsaturation.

4. A 4-hydrocarbyloxyaryl-l,1,2-tricyano-1,3-butadiene having theformula CN ON ROArCH=OHO=( J Where Ar is arylene which is entirelyhydrocarbon of no more than 20 carbons and has the two bonds stemmingfrom different carbons of the arylene ring, and R0 is a hydrocarbyloxygroup free of aliphatic carbon-to-carbon unsaturation and of no morethan 20 carbons.

5. A 4-hydrocarbyloxyaryl-1,l,2-tricyano-1,3-butadiene having theformula R 31 ON ON ROAr( 3=(il( 3=( J (ilN where R and R are hydrocarbylgroups free of aliphatic carbon-to-carbon unsaturation, Ar is arylenewhich is entirely hydrocarbon of no more than 20 carbons and has the twobonds stemming from difierent carbons of the arylene ring, and R0 isalkoxy.

6. A 4-hydrocarbyloxyaryl-l,l,Z-tricyano-1,3-butadiene having theformula where one of the groups R and R is hydrogen and the other is ahydrocarbyl group free of aliphatic carbon-tocarbon unsaturation, AI isarylene which is entirely hydrocarbon of no more than 20 carbons and hasthe two bonds stemming from different carbons of the arylene ring, andR0 is alkoxy.

7. A 4hydrocarbyloxyaryl-l,1,2-tricyano-l,3-butadiene having the formulawhere AI is arylene which is entirely hydrocarbon of no more than 20carbons and has the two bonds stemming from different carbons of thearylene ring, and R0 is alkoxy.

8. A 4-hydrocarbyloXyaryl-l,l,Z-tricyano-l,3-butadiene having theformula where R and R are hydrocarbyl groups free of aliphaticcarbon-to-carbon unsaturation, Ar is phenylene, and R0 is alkoxy.

9. A 4-hydrocarbyloxyaryl-1,l,2-tricyano-l,3-butadiene having theformula where one of the groups R and R is hydrogen and the other is ahydrocarbyl group free of aliphatic carbon-tocarbon unsaturation and ofno more than 20 carbons, A is phenylene, and R0 is alkoxy of no morethan 20 carbons.

10. A 4-hydrocarbyloXyaryl-1,l,Z-tricyano-1,3-butadiene having theformula where Ar is phenylene, and R0 is alkoxy of no more than 20carbons.

l l. 4-(p-methoxyphenyl)-l,1,2-tricyano-1,3-butadiene. 12. Process whichcomprises heating in the range of 25 to 260 C. and in contact with alower alkanol, a 3-hydrocarbyloxyaryl-1,l,2,2-tetracyanocyclobutanehaving the formula R1 0N RO-Ar( 3(3CN Rr-(E-C-GN II HCN where Ar isarylene which is entirely hydrocarbon of no more than 20 carbons and hasthe two bonds stemming from different carbons of the arylene ring, andR0 is a hydrocarbyloxy group free of aliphatic carbon-to-carbonunsaturation, and obtaining as the resulting product a4-hydrocarbyloXyaryl-1, 1,2-tricyano-1, 3-butadiene.

14. Process which comprises heating in the range of 25 to 200 C. and incontact with a lower alkanol, a 3-hydrocarbyloxyaryl-ll,2,Z-tetracyanocyclobutane having the formula where one of the groups Rand R is hydrogen and the other is a hydrocarbyl group free of aliphaticcarbon-tocarbon unsaturation, Ar is arylene which is entirelyhydrocarbon of no more than 20 carbons and has the two bonds stemmingfrom different carbons of the arylene ring, and R0 is alkoxy, andobtaining as the resulting product a 4-hydrocarbyloxyaryl-l,l,2-tricyano-1, 3 -butadiene.

15. Process which comprises heating in the range of 25 to 200 C. and incontact with a lower alkanol, aS-hydrocarbyloxyaryl-l,l,2,2-tetracyanocyclobutane having the formulawhere Ar is arylene which is entirely hydrocarbon of no more than 20carbons and has the two bonds stemming from different carbons of thearylene ring, and R0 is alkoxy, and obtaining as the resulting product a4-hydrocaroyloxyaryl-l 1,2-tricyanol ,3 -butadiene.

16. Process which comprises heating in the range of 25 to 209 C. and incontact with a lower alkanol, a3-hydrocaroyloxyaryl-l,l,2,2-tetracyanocyclobutane having the formulaHON where R and R are hydrocarbyl groups free of aliphaticcarbon-to-carbon unsaturation, Ar is phenylene, and R0 is alkoxy, andobtaining as the resulting product a4-hydrocarbyloxyar'yl-l,1,2-tricyano-1,3-butadiene.

17. Process which comprises heating in the range of 25 to 200 C. and incontact with a lower alkanol, a3-hydrocarbyloxyaryl-1,1,2,2-tetracyanocyclobutane having the formula18. Process which comprises heating in the range of 20 25 to 200 C. andin contact with a lower alkanol, a

3-hydrocarbyloXyaryl-l, l, 2,2-tetracyanocyclobutane having the formulaWhere Ar is phenylene, and R0 is alkoxy of no more than 20 carbons, andobtaining as the resulting product a 4-hydrocarbyloXyary1-1, l,2-tricyano-1,S-butadiene.

19. Process which comprises heating in the range of 25 to 200 C. and incontact with a lower alkanol,S-(p-methoxyphenyl)-1,1,2,2-tetracyanocyclobutane and obtaining as theresulting product 4 (p-methoxyphenyl)- 1,1,Z-tricyano-l,B-butadiene.

References Cited in the file of this patent UNITED STATES PATENTS2,762,833 Heckert Sept. 11, 1956

1. A 4-HYDROCARBYLOXYARYL-1,1,2-TRICYANO-1,3-BUTADIENE HAVING THEFORMULA